Can't connect to Internet at work

Hello there: this thread caught my interest, though my problem is a bit different. I have a HP laptop running windows 7 64bit . I can connect wirelessly at coffee shops, motels, at home but out of the blue I can not connect to intenet at my office. wireless connects to local network and runs fine, but no internet. have tried to use ethernet cable but same results. have two other laptops on this network with internet access and also a desktop that has access though not wireless as are the laptops. Totally confused by this one any ideas I can try ?

ok more input I am at my work i use logmein hamachi network and with wireless i have no connection with others on this network but if i use the ethernet cable i have connection to my computer at home, but with IE11 or mozilla-firefox 24.0 i still have no access to internet

thanks Paul
There is not any proxy set on any of my computers. I feel I must say again that this laptop can connect everywhere else, coffee shops, sams clubs, and maybe more. It is just at my work that it has decided to not connect to the internet. It had been connecting at one time.

This could be one of those anomalous faults that will probably resolve itself, but in the mean time, isn't going to help you.

Have you tried any of your restore points back to when you could connect or try assigning your wireless adapter with a static IP address.

You will need to have a word with your works IT department as to the best IP address to use, should it conflict with any other peripherals or they could set up your computer as a Fixed Host with a reserved IP address within the router, to see if that does it.

An assigned static IP address set up in the computer may need to be reverted to DHCP for when you are using other locations to prevent an IP address conflict.

Just as a matter of interest, Firefox was updated to v28.0 today from v27.0.1

At many work sites it's mandatory that your network configuration is done via DHCP and that you use their supplied DNS server(s). If you are manually overriding any of these DHCP assigned settings (even manually setting the same IP address you might otherwise be assigned will not work in many cases) you are likely to have trouble. Especially true in the case of DNS as a common problem I see with the rise of BYOD into work sites is users that manually configure specific DNS servers, use an app to lock their DNS servers (Comcast's Constant Guard for example), or have some malware that overrides the assigned DNS servers; who while connected to the Internet really can't go anywhere because they're getting no DNS resolution as these firms block access to port 53 (DNS port) from all but their own servers.